Ilocos Sur, which at the time included the sub-province of Abra, was initially divided in 1907 into three representative districts. Abra was last represented as part of the province's now-defunct third district in 1917, after its re-establishment as a regular province on March 10, 1917, by virtue of Act No. 2683 warranted its separate representation, thereby reducing Ilocos Sur to two districts.[1]
When the Philippine Commission detached Tagudin from Ilocos Sur and made it the capital of the sub-province of Amburayan in Mountain Province on May 15, 1907, by virtue of Act No. 1646, the town's residents were still allowed to vote as part of the Ilocos Sur's second district.[2] This arrangement was terminated on August 10, 1916, under Act No. 2657 (the Administrative Code of the Philippine Islands), which removed the town from the second district.[3]
The enactment of Act No. 2877 in 1920 reorganized northwestern Luzon, by abolishing the sub-province of Amburayan in the undivided Mountain Province and annexing several of its municipal entities—Alilem, Sigay, Sugpon, Suyo and its capital Tagudin—to Ilocos Sur. The Lepanto sub-province townships of Angaki, Concepcion, San Emilio and its capital Cervantes were also placed under the jurisdiction of Ilocos Sur. However residents of these areas remained represented by the Mountain Province's appointed assembly members until they were finally extended the right to vote in assembly district elections in 1935, after the passage of Act No. 4203 placed them in the second district of Ilocos Sur.[4]
^ abcdefghiAnnexed to Ilocos Sur on February 4, 1920, but remained represented as part of the representation of Mountain Province until 1935. Extended the right to elect the representative of the second district of Ilocos Sur in 1935.
^Removed from list of members of the House of Representatives on January 25, 1960, after running in the November 10, 1959, election for governor of Ilocos Sur.[6]
^Only took oath of office for second term on January 21, 1969,[6] following a long legal battle over results of election contested by retired Brig. Gen. Lucas V. Cauton.[7]
^Annexed to Amburayan sub-province, Mountain Province May 15, 1907, but remained represented as part of the first district of Ilocos Sur until the arrangement was terminated on August 10, 1916, by virtue of Act No. 2657.